US3687123A

US3687123A - Controlled electrical pulse source

Info

Publication number: US3687123A
Application number: US492570A
Authority: US
Inventors: Floyd M Minks
Original assignee: Individual
Current assignee: Individual
Priority date: 1965-10-04
Filing date: 1965-10-04
Publication date: 1972-08-29
Anticipated expiration: 1989-08-29

Abstract

A triggered blocking oscillator includes a charging transistor connected in series with the primary of an oscillator transformer which includes a secondary connected in series with a diode to charge a capacitor. The capacitor is also connected to the engine distributor in series with a silicon controlled rectifier. The transformer includes a control winding connected to fire the rectifier. A control transistor is connected in the base circuit of the main charging control transistor with the input of the control transistor connected in circuit through a silicon controlled rectifier. The gate of the silicon controlled rectifier and the base of the control transistor are connected to a battery in series with breaker points of the internalcombustion engine to provide periodic turn-on pulses to the silicon controlled rectifier and transistor. A square loop core unit is connected to divert current from the silicon controlled rectifier and the input of the control transistor. When the circuit is first turned on, the current increases until such time as the square loop core unit is saturated. At that time, the reactance of the square loop core unit decreases diverting the current around the silicon controlled rectifier and control transistor and effectively turning them off. This, in turn, turns off the main transistor and provides the pulse transfer.

Description

United tates Patent Minlss Aug. 29, 1972 [54] CONTROLLED ELECTRICAL PULSE SOURCE [72] Inventor: Eloydlt'l: RT. #1, Port Washington, ll/K531? [22] Filed: Oct. 4,1965

21 Appl. No.: 492,570

[52] US. Cl. ..123/148 E, 315/209 [51] Int. Cl ..F02d 11/10 [58] Field of Search ..123/148 E; 315/209 CD; 33l/1l2,146,148, 149

[5 6] References Cited UNITED STATES PATENTS 3,297,911 l/1967 Quinn ..315/214 3,302,629 2/1967 Shano ..123/148 E 3,312,211 4/1967 Boyer ..123/148 E Primary Examiner--Laurence M. Goodridge AttorneyAndrus, Sceales, Starke & Sawall [57] ABSTRACT A triggered blocking oscillator includes a charging transistor connected in series with the primary of an oscillator transformer which includes a secondary connected in series with a diode to charge a capacitor. The capacitor is also connected to the engine distributor in series with a silicon controlled rectifier. The transformer includes a control winding connected to fire the rectifier. A control transistor is connected in the base circuit of the main charging control transistor with the input of the control transistor connected in circuit through a silicon controlled rectifier. The gate of the silicon controlled rectifier and the base of the control transistor are connected to a battery in series with breaker points of the internal-combustion engine to provide periodic turn-on pulses to the silicon controlled rectifier and transistor. A square loop core unit is connected to divert current from the silicon controlled rectifier and the input of the control transistor. When the circuit is first turned on, the current increases until such time as the square loop core unit is saturated. At that time, the reactance of the square loop core unit decreases diverting the current around the silicon controlled rectifier and control transistor and effectively turning them off. This, in turn, turns off the main transistor and provides the pulse transfer.

7 Claims, 1 Drawing Figure do as PATENTEnAucze m2 INVENTOR. FLOYD M. MINKS BY 74n drus Siarl@ AfFonwsYs CONTROLLED ELECTRICAL PULSE SOURCE This invention relates to a controlled electrical pulse source and particularly to a pulse source for capacitor discharge ignition systems for internal-combustion engines and the like.

Electronic ignition systems for internal-combustion engines have been suggested for a number of years wherein a capacitor is charged from the battery and/or the generator and is rapidly discharged through the induction coil of the usual ignition unit to fire a spark plug. The recent development of solid state devices such as transistors, silicon controlled rectifiers and the like provided a highly satisfactory amplifying and switching means for controlled charging and switching of the capacitor circuit. A highly satisfactory capacitor discharge ignition system is shown in applicants copending application entitled Capacitor Ignition System which was filed on Mar. 1, 1965 with Ser. No. 436,118, now US. Pat. No. 3,369,151.

The present invention is directed to an improved pulse source particularly applicable to capacitor discharge systems wherein the amount of energy for each pulse is regulated through a control means connected in the charging circuit for the capacitor. Generally, in accordance with the present invention, a triggered blocking oscillator of an improved and novel construction is provided having a control circuit connected in the feedback circuit to determine the time that each pulse begins and the energy per pulse. In a preferred construction, a transistor is connected in series with the primary of an oscillator transformer means. Timed switching means are provided for periodically initiating conduction through the transistor to provide a pulse from the battery or other direct current (D.C.) source to the transformer primary. The switching means is connected in a feedback loop control having a magnetic core unit connected in the circuit to permit conduction of said switch means until the core of the unit is saturated at which time the rapid change in the permeability of the core unit'causes a diversion of current and turn-off of the transistor. The core unit may advantageously employ a square loop type core material; that is, one with essentially a rectangular magnetic characteristic. The transistor rapidly turns off causing a decay in the flux in the transformer. At this time, the transformer provides an output pulse charging the capacitor which is subsequently discharged to the ignition spark plug or other ignition unit of the internal-combustion engine.

In a preferred construction of the present invention, the triggering and the feedback circuit employs a control transistor connected in the base circuit of the main charging control transistor with the input of the control transistor connected in circuit through a silicon controlled rectifier or the like. The gate of the silicon controlled rectifier and the base of the control transistor are connected to a suitable signal source which in turn is controlled in accordance with the timing of the internal-combustion engine to provide periodic turn-on pulses to the silicon controlled rectifier and transistor. The square loop core unit is connected to divert current from the silicon controlled rectifier and the input of the control transistor. Consequently, when the circuit is first turned on, the current increases until such time as the square loop core unit is saturated. At that time, the reactance of the square loop core unit decreases diverting the current around the silicon controlled rectifier and control transistor and effectively turning them off. This, in turn, turns off the main transistor and provides the pulse transfer as noted above. Thus, the conduction is initiated by the tum-on pulse and terminated by the magnetic energy regulator. The unit therefore acts as a gated or triggered oscillator and not as an amplifier of the input pulse.

The present invention thus provides a highly efficient means for regulating the energy per pulse for capacitor discharge ignition systems and thelike. The circuit of the present invention provides a desired output over a wide variation in the input and essentially eliminates variation in engine performance with changes in battery or source voltage. This will prevent generation of abnormally damaging voltages or currents in the operating circuit or the ignition system with variation in the input voltage or the gain of the semi-conductors and will maintain the same performance with these as well as variation in speed. The output energy is also independent of the value of the capacitor 5 over a broad range of capacity values.

The drawing furnished herewith illustrates a preferred construction of the present invention in which the above advantages and features are clearly disclosed as well as others which will be clear from the following description of the drawing.

The drawing is a schematic circuit diagram of an ignition system constructed in accordance with the present invention.

Referring to the drawing, the illustrated ignition system is connected to a direct current source such as a low voltage battery 1 having a suitable rated output voltage such as 6, 12 or 24 volts all of which are presently employed in automobiles, trucks, outboard motors or other similar internal-combustion engines. A single spark gap 2 is illustrated forming a part of a combustion chamber of the prime mover. In multicylinder engines, a plurality of spark gaps will normally be employed with a distributor 3, shown in block diagram, provided to sequentially distribute the power to the several gaps in accordance with known practice. The illustrated embodiment of the present invention employs a pulse transformer 4 which couples the spark gap 2 to a capacitor discharge circuit including a storage capacitor 5 connected to be discharged through the transformer 4 in series with a silicon controlled rectifier 6. A firing control transformer winding 7 is connected to the rectifier 6 and provides controlled firing thereof in timed relation to the operation of the internal-combustion engine and the distributor 3 as hereinafter described and thereby causes proper transfer of energy from the capacitor 5 to gap 2.

The capacitor 5 is connected to be charged from the battery 1 through a triggered blocking oscillator 8 which includes a square loop core unit 9 to regulate the energy per pulse as hereinafter described.

An input switch 10 is coupled to be actuated in synchronism with the operation of the engine, diagrammatically shown coupled to the operation of the distributor 3, to provide periodic triggering of the blocking oscillator 8 into conduction.

The oscillator 8 generally includes a charging transistor 11 connected in series with a primary 12 of a transfer or oscillating transformer 13. A secondary l4 of transformer 13 is connected in a charging circuit with the capacitor 5, as hereinafter described. The circuit is such that during the conduction through the primary 12 from the battery 1 the capacitor circuit is effectively opened. When the current through the transformer primary 12 is cut ofi, a pulse is generated in the secondary which is conducted to charge the capacitor 5. This charge is transmitted to the gap 2 as noted above at the initiation of the subsequent charging of the transformer 13.

Generally, the circuit operation includes the opening of the switch 11 to initiate operation of the oscillator 8 which derives power from the battery 1 with a portion of the current passing through the square loop core unit 9. When the square loop core unit is saturated however it will rapidly turn off the oscillator 8 and the collapsing field in transformer 13 produces a current in the secondary M which charges capacitor 5 to a corresponding level. The square loop core unit 9 determines the on time of the oscillator 8 as a function of the battery voltage and therefore regulates the energy in the pulse transferred to the capacitor 5. The silicon controlled rectifier 6 is fired therefore by a pulse generated in winding 7, which is wound as a part of transformer 13, during the initial conduction of oscillator 8 and in timed relation to the operation of the distributor 3 and the movement of the piston, not shown, to provide proper transfer of energy from the capacitor 5 through the pulse transformer 4 to the gap 2.

More particularly in the illustrated embodiment of the invention, the oscillator circuit includes the transistor 11, shown as a PNP type, connected in a common emitter configuration; having an emitter 16, as an input-output element, connected to the positive side of the battery 1 and a collector 17, as an output element, connected to the one side of the primary winding 12. The opposite side of the transformer primary winding 12 is connected to the negative side of the battery 1 through a common ground connection 18. The transistor 11 includes a base 19 as the input element which is connected to derive its power from the battery 1 as follows. The base 19 is connected to the negative terminal of the battery 1 through a dropping resistor 20 and a transistor 21 to ground which controls the turning on or conduction through the transistor 11.

The transistor 21 is shown as an NPN type having the collector connected through resistor 20 to the base 19 and the emitter 23 connected to the ground. terminal 18. An input base 24 of the transistor 21 is connected to derive power from the collector 17 of transistor 11 after initiation of the triggering of the blocking oscillator 8. The connection to the collector 17 is through a resistor 25, a resistor 26 and a sil con controlled rectifier 27 to provide a selectively completed or triggered voltage dividing network. Thus, the feedback winding commonly used in blocking oscillators is eliminated. A feedback winding could be used; for example, other considerations necessitated the grounding of collector 17 of transistor 11.

The silicon controlled rectifier 27 includes an anode 28 connected to the adjacent series resistor 26 and the cathode 29 connected to the base 24 of transistor 21. A gate 30 of the silicon controlled rectifier 27 controls conduction through the rectifier from the anode 28 to the cathode 29. The gate 30 is connected to the positive side of the battery 1 through a direct current blocking capacitor 31 and the resistor 32. Switch 10 is connected between the negative side of battery 1 and the junction of capacitor 31 and resistor 32. Thus, whenever switch 10 is open, a circuit is momentarily completed from the positive side of the battery through the resistor 32, capacitor 31, gate 30 and cathode 29 to the base 24 of transistor 21 and then through the emitter 23 to the negative side of the battery 1 and ground 18. Consequently, the silicon controlled rectifier 27 and transistor 21 will be biased to conduct and permit current to flow and provide an input bias on the transistor which in turn provides an inputsignal on the base 19 of transistor 11. Regenerative action to the base 24 of the transistor 21 causes it to conduct at a greater rate. The current will thus increase through the transistors 11 and 21 and the series connected transformer primary 12 with the energy being stored in the core 15. The square loop core unit 9 is connected to cut off conduction.

When the switch 10 again closes, capacitor 31 discharges through resistor 33.

The illustrated pulse forming circuit including switch 10 has been shown for purposes of clearly illustrating the functioning of the oscillator and may be replaced with any other appropriate timing means adapted to generate a short duration pulse.

The core unit 9 may be of any known or suitable construction and is diagrammatically shown including a winding 34 wound on a square loop core 35. Thus, the inductance of winding 34 is relatively high until the knee of the core characteristic is reached and then rapidly changes to a relatively very small value. Winding 34 is connected between the junction of

resistors

25 and 26 and the emitter 23 of transistor 21 and thus directly across the circuit of the silicon controlled rectifier 27 and the input circuit of the transistor 21. When transistor 11 begins to conduct, a part of the current is diverted through the winding 34 of square loop core unit 9 which provides a relatively high impedance to the current flow until it reaches saturation. When it changes to the saturated condition, the reactance reduces substantially and essentially to zero and provides a direct bypass or shunt around the silicon controlled rectifier 27 and the input circuit of the transistor 21. The silicon controlled rectifier 27 and the transistor 21 stop conducting and the bias on the base 19 of the transistor 11 is removed. This opens the circuit from the battery 1 to stop the input current flow. The

voltage dividing resistors

25 and 26 are provided to insure reset of the unit 9 and to prevent excessive current in the circuit when unit 9 is saturated.

The core unit 9 thus acts as a switch sensitive to the volt-time integral applied to it. In the broadest aspect of the present invention, other switch means including semi-conductors connected to be turned on by either the volt-time integral applied or by the current through winding 12 of transformer 13, which is proportional to the volt-time integral, can be employed to regulate the energy in each cycle or single pulse generated by the oscillator.

When the core unit 9 terminates conduction, the magnetic field in the core 15 of the transformer 13 collapses and induces a voltage of opposite polarity in the secondary winding 14 to cause a current flow through the Capacitor charging circuit which includes a blocking diode 36, a protective diode 37 and a resistor 38 connected to the positive side of the capacitor 5. The opposite side of the capacitor 5 is connected to the opposite side of the transformer secondary 14. This will permit charging of the capacitor to the selected value determined by the cutoff of the oscillator 8 through the action of the square loop core 9.

The capacitor 5 subsequently discharges through transformer 4 by triggering of the silicon controlled rectifier 6.

Transformer 4 includes a primary 39 connected in series with the silicon controlled rectifier 6 directly across the capacitor 5. The illustrated transformer 4 includes a secondary 40 connected across the spark gap 2 in series with the distributor 3.

The silicon controlled rectifier 6 generally corresponds to the rectifier 27 and includes a gate 41 connected to the trigger winding 7 which is wound as a small secondary on the oscillator transformer 13. Winding 7 is wound with respect to the primary 12 to provide a trigger pulse during the starting cycle of the oscillator 8. Consequently, when the switch is opened to initiate operation of the oscillator 8, the transformer winding 7 produces a firing pulse which causes rectifier 6 to conduct and discharge the previous charge on the capacitor 5 through the pulse transformer 4 for firing of the spark gap 2.

Generally, in accordance with the teaching of applicants previously identified copending application, a Zener diode is connected in parallel with the silicon controlled rectifier as a protective device.

Additionally, in the illustrated embodiment of the invention, a simple tachometer circuit is connected in the circuit with the square loop core unit 9 to provide an inexpensive speed readout device. The tachometer circuit includes a tachometer meter 43 connected in series with a diode 44 and a resistor 45 between the junction of

resistors

25 and 26 and thus the common connection to the square loop core unit 9. The opposite side of the tachometer meter 43 is connected to ground as shown at 46. The volt-time integral across the square loop core unit 9 is essentially the same for all battery voltages. The oscillator circuit generally produces a volt-time integral which is independent of battery voltage and consequently the tachometer circuit may also be connected directly across the primary 12. The tachometer meter 43 indicates the average current and consequently gives an output signal directly proportional to the speed at which the engine is turning over.

The operation of the illustrated embodiment of the invention may be briefly summarized as follows.

The switch 10 is coupled to the distributor 3 to be driven in accordance with the movement of the pistons of the internal-combustion engine in accordance with any suitable or known system. The battery 1 provides a source of energy to the oscillator 8 which is transferred to the capacitor 5 to charge it to a selected level whenever the switch 10 is opened to initiate conduction through a gate circuit of silicon controlled rectifier 27 and the input or base loop of transistor 21. The transistor 11 then conducts and provides a charging current until the square loop core unit 9 is saturated at which time it rapidly turns the oscillator off, terminating the charging of the transformer 13 and transferring a charging pulse to the capacitor 5.

The next time the switch 10 is opened the charging cycle is again initiated. The winding 7 fires the silicon controlled rectifier 6 and completes the discharge circuit for the capacitor 5 through the pulse transformer 4. The capacitor 5 is therefore rapidly discharged through the pulse transformer to fire the proper spark gap 2 or the like during the charging of the transform er 13. The capacitor 5 cannot discharge back to the transformer 13 as a result of the blocking diode 36.

The present invention provides a unique blocking oscillator employing a controlled rectifier connected in the input circuit of the transistor or similar electronic switch means to initiate conduction. The controlled rectifier may be connected directly in circuit with the main oscillator transistor 11 with the gate-circuit in series with the input elements of the transistor. Further, the preferred circuit employing the two transistors provides a unique circuit for driving the oscillator with power derived directly from the battery or other input power source.

The present invention thus provides an improved blocking oscillator which provides a highly efficient means for controlling the charging of the capacitor 5 to a preselected level and maintains essentially predetermined constant operation independently of the level of the voltage source over a wide variation in the voltage level thereof as well as the operating speed of the engine over the ranges selected and determined by the particular value of the several components in the system. This energy level is primarily dependent upon the characteristics of the core unit 9 and transformer 13 and to a slight extent the

resistors

25 and 26 and is essentially independent of the exact value of the switching element parameters of the oscillator such as gain of the transistor and the exact value of the capacitor 5.

For purposes of the present invention, a blocking oscillator includes an inductive energy storage means connected to an energy source through a switch means having at least one input means connected to derive power in a feedback loop from the output and the storage means is connected in an output circuit to deliver the stored energy upon the decrease of current into the inductive energy storage means.

Various modes of carrying out the invention are contemplated as being within the scope of the following claims particularly pointing out and distinctly claiming the subject matter which is regarded as the invention.

I claim:

1. An ignition system for an internal-combustion engine,

energy source means for the ignition system,

a blocking oscillator having an electronic switch means in series with an inductive energy storage means, said switch means having input elements to initiate conduction and generation of a charging pulse signal to said energy storage means and a square loop magnetic core unit connected in the output circuit of the switch means to conduct only after the switch means has initiated conduction to said energy storage means and operable to stop conduction through the switch means to generate a single pulse of electrical energy and thereby provide a preselected energy per pulse stored in the inductive means essentially independent of changes in engine speed and potential of said source means,

means connected to said input elements to initiate said cycle independently of said square loop magnetic core unit, and

output circuit means to transfer the energy from the inductive means for firing of the engine.

2. In an ignition system for internal-combustion engines and the like having igniting means in a combustion chamber to be fired from a source of current, comprising a capacitor,

a blocking oscillator means having an output means connected across the capacitor and having an electronic switch for connecting the output means to the source and including a magnetic control unit connected to the output of the electronic switch and connected to effectively open said switch means in response to saturation of the magnetic control unit,

an input signal means separate from said magnetic control unit and connected to the switch means for effectively closing the switch means and initiating a charging cycle independently of said magnetic control unit, and

an output circuit connected to the capacitor and having output means adapted to be connected to the igniting means for firing thereof and including circuit completing control means.

3. In a capacitor discharge ignition system for an internal-combustion engine,

a blocking oscillator having an inductive storage means,

a controlled rectifier connected to initiate a cycle of the blocking oscillator for generating a single pulse of current,

means to trigger the rectifier in accordance with the ignition requirement of the engine,

a switch means separate from said rectifier and connected in an output circuit of the oscillator in parallel with said rectifier and energized by said pulse of current and responsive to a selected volttime integral to turn off the oscillator and terminate said single pulse of current,

a capacitor connected to the inductive storage means and charged in response to termination of the pulse, and

firing means to discharge the capacitor in timed relation to engine operation.

4. In anignition system f or internal-combustion engines and the like having igniting means in a combustion chamber to be fired from a source of direct current, comprising a capacitor,

a blocking oscillator having an output means connected across the capacitor and having a first transistor connecting the output means to a source and a second transistor connected in the input circuit of the first transistor, said oscillator including a gate controlled rectifier connecting the output of the first transistor to the input of the second transistor,

a switch means responsive to the volt-time integral impressed thereon and connected in parallel with the gate controlled rectifier and effective to turn off the gate controlled rectifier,

an output circuit connected to the capacitor and having output means adapted to be connected to the igniting means for firing thereof and including control switch means, and a firing circuit connected to control the switching means and actuate it to cause firing of the ignition means. 5. The ignition system of claim 4 wherein said switch means is a magnetic unit having a winding connected in parallel with the controlled rectifier and the input of the second transistor, said magnetic unit turning off said control rectifier and said transistor upon saturation of the magnetic unit.

6. In an ignition system for internal-combustion engines and the like having igniting means in a combustion chamber to be fired from a source of direct current, comprising a capacitor,

a blocking oscillator including an oscillator output transformer and a first transistor connected in a series circuit with a power connection means and having a control transistor connected in series with an input element of the first transistor to the power connection means, said oscillator having a con trolled rectifier connected in a series circuit with an output element of the first transistor and an input element of the second transistor, said series circuit including a pair of voltage dividing element connected between the rectifier and the output element,

means operable in timed relation to the engine and connected to trigger the controlled rectifier to initiate a charging cycle,

a square loop core unit having a winding connected at one end to the junction of the voltage dividing elements and at the opposite end to an output element of the second transistor and turning off the oscillator in response to a selected current through said winding,

circuit means connecting said capacitor to said oscillator output transformer to charge the capacitor when the oscillator turns off, and

means for connecting the capacitor to the igniting means and to the blocking oscillator and selectively operated in response to initiation of the charging cycle to discharge said capacitor.

7. A capacitor discharge ignition system for an internal-combustion engine having a firing means and a battery, the improvement in the connection of the battery to the firing means comprising a blocking oscillator having an inductive storage means and an energy source connection means,

a main transistor having an input element, an output element and a common input-output element, the output element and the common input-output element being connected in a series circuit loop with the storage means and the energy source connection means,

a control transistor having an input element, an output element and a common input-output element, the output element and the common input-output element of the control transistor being connected,

in a series control loop with the input element and the common input-output element of the main transistor and the energy source connection means,

9 10 means including a controlled rectifier for initiating a controlled rectifier and turning off the oscillator in cycle of the blocking oscillator and connecting the response to the volt-time integral of the oscillator input element of the control transistor to the outoutp i, and put element of the main transistor to derive a con- 3 eapaeltor Connected to the storege means and trol feedback signal from the main transistor for 5 adapteqto be connected 9 the firlng means to be sustaining that cycle of the blocking oscillator, sequentlany charged and dischargedmeans paralleled with the control transistor and the UNITED STATES PATENT oTTTcE QERTIFICATE 0F QQRRECHQN.

Patent No. 3 687 123 Dated Auqust 29 1972 Inventoflx) FLOYD M. MINKS It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Title Page After Paragraph [21] insert vnew paragraph [73] Assignee Brunswick Corporation, Chicago, Illinois Signed and sealed this 3rd day of April 1973.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissioner of Patents ORM PO-1050(10-69) USCOMM-DC 60376-1 69 3 U45. GOVERNMENT PRIN ING OFFICE: 1969 0-366-334,

Claims

1. An ignition system for an internal-combustion engine, energy source means for the ignition system, a blocking oscillator having an electronic switch means in series with an inductive energy storage means, said switch means having input elements to initiate conduction and generation of a charging pulse signal to said energy storage means and a square loop magnetic core unit connected in the output circuit of the switch means to conduct only after the switch means has initiated conduction to said energy storage means and operable to stop conduction through the switch means to generate a single pulse of electrical energy and thereby provide a preselected energy per pulse stored in the inductive means essentially independent of changes in engine speed and potential of said source means, means connected to said input elements to initiate said cycle independently of said square loop magnetic core unit, and output circuit means to transfer the energy from the inductive means for firing of the engine.

2. In an ignition system for internal-combustion engines and the like having igniting means in a combustion chamber to be fired from a source of current, comprising a capacitor, a blocking oscillator means having an output means connected across the capacitor and having an electronic switch for connecting the output means to the source and including a magnetic control unit connected to the output of the electronic switch and connected to effectively open said switch means in response to saturation of the magnetic control unit, an input signal means separate from said magnetic control unit and connected to the switch means for effectively closing the switch means and initiating a charging cycle independently of said magnetic control unit, and an output circuit connected to the capacitor and having output means adapted to be connected to the igniting means for firing thereof and including circuit completing control means.

3. In a capacitor discharge ignition system for an internal-combustion engine, a blocking oscillator having an inductive storage means, a controlled rectifier connected to initiate a cycle of the blocking oscillator for generating a single pulse of current, means to trigger the rectifier in accordance with the ignition requirement of the engine, a switch means separate from said rectifier and connected in an output circuit of the oscillator in parallel with said rectifier and energized by said pulse of current and responsive to a Selected volt-time integral to turn off the oscillator and terminate said single pulse of current, a capacitor connected to the inductive storage means and charged in response to termination of the pulse, and firing means to discharge the capacitor in timed relation to engine operation.

4. In an ignition system f or internal-combustion engines and the like having igniting means in a combustion chamber to be fired from a source of direct current, comprising a capacitor, a blocking oscillator having an output means connected across the capacitor and having a first transistor connecting the output means to a source and a second transistor connected in the input circuit of the first transistor, said oscillator including a gate controlled rectifier connecting the output of the first transistor to the input of the second transistor, a switch means responsive to the volt-time integral impressed thereon and connected in parallel with the gate controlled rectifier and effective to turn off the gate controlled rectifier, an output circuit connected to the capacitor and having output means adapted to be connected to the igniting means for firing thereof and including control switch means, and a firing circuit connected to control the switching means and actuate it to cause firing of the ignition means.

5. The ignition system of claim 4 wherein said switch means is a magnetic unit having a winding connected in parallel with the controlled rectifier and the input of the second transistor, said magnetic unit turning off said control rectifier and said transistor upon saturation of the magnetic unit.

6. In an ignition system for internal-combustion engines and the like having igniting means in a combustion chamber to be fired from a source of direct current, comprising a capacitor, a blocking oscillator including an oscillator output transformer and a first transistor connected in a series circuit with a power connection means and having a control transistor connected in series with an input element of the first transistor to the power connection means, said oscillator having a controlled rectifier connected in a series circuit with an output element of the first transistor and an input element of the second transistor, said series circuit including a pair of voltage dividing element connected between the rectifier and the output element, means operable in timed relation to the engine and connected to trigger the controlled rectifier to initiate a charging cycle, a square loop core unit having a winding connected at one end to the junction of the voltage dividing elements and at the opposite end to an output element of the second transistor and turning off the oscillator in response to a selected current through said winding, circuit means connecting said capacitor to said oscillator output transformer to charge the capacitor when the oscillator turns off, and means for connecting the capacitor to the igniting means and to the blocking oscillator and selectively operated in response to initiation of the charging cycle to discharge said capacitor.

7. A capacitor discharge ignition system for an internal-combustion engine having a firing means and a battery, the improvement in the connection of the battery to the firing means comprising a blocking oscillator having an inductive storage means and an energy source connection means, a main transistor having an input element, an output element and a common input-output element, the output element and the common input-output element being connected in a series circuit loop with the storage means and the energy source connection means, a control transistor having an input element, an output element and a common input-output element, the output element and the common input-output element of the control transistor being connected in a series control loop with the input element and the common input-output element of the main transistor and the energy source coNnection means, means including a controlled rectifier for initiating a cycle of the blocking oscillator and connecting the input element of the control transistor to the output element of the main transistor to derive a control feedback signal from the main transistor for sustaining that cycle of the blocking oscillator, means paralleled with the control transistor and the controlled rectifier and turning off the oscillator in response to the volt-time integral of the oscillator output, and a capacitor connected to the storage means and adapted to be connected to the firing means to be sequentially charged and discharged.